1. Field of Invention
This invention relates to graphic interface devices, commonly called graphic or X-Y digitizing tablets, mice, track balls, light pens, joy sticks or knob boxes which allow graphic data to be input into computers, for example. Specifically, the invention relates to an improved, miniaturized, finger worn X-Y graphic interface device which can emulate a mouse.
2. Discussion of Prior Art
The following discussion will often refer to computers as an example of a device which requires or can benefit from my invention. It is not intended to imply that computers are the only devices which will work with this invention. For example, this invention could be used to control steering, acceleration and braking of a vehicle such as a wheelchair or for other purposes.
Heretofore, apart from a conventional keyboard, interfacing with a computer has been limited to devices which are hand operated and physically separated from the keyboard. These devices require that one's hand be physically moved from the main keyboard and that an interface implement be manipulated using one's entire arm, wrist or fingers.
Mouse type devices which are moved over a surface by hand motion are discussed in U.S. Pat. Nos. 4,550,316 (Whetstone, et al), 4,613,853 (Hosogoe, et al), 4,698,626 (Sato, et al) and 4,564,835 (Dhawan). A small ball inside the mouse, jutting out slightly from the bottom, is rolled on the work surface by the operator and therefore requires adequate frictional contact between the ball and the work surface. It should be noted that mice based on optical principles require a special pad or surface to operate upon, while mechanical mice contain moving parts that can gather dirt and dust while being used. Mice also contain at least one electrical switch which can be activated when a particular position is reached or can remain activated while one is moving the mouse over a surface.
Mitch, U.S. Pat. No. 4,520,355 teaches the use of a joystick which is basically a mechano-electric device with moving parts prone to wear and must be grasped by the hand and fingers for use. Its function is commonly accomplished through the use of internally mounted mechanical potentiometers capable of separating out the mutually orthogonal movements of the joystick. Usually mounted in some sort of package which would sit to the side of the main keyboard, it requires motion of the arm and wrist for access and operation.
The track ball as taught in U.S. Pat. No. 3,625,083 of Bose is another known device used for graphic interfacing. An "upside down" mouse contains a ball which juts out slightly above its top surface. Since it is usually set off to the side of the keyboard, one must move the hand over to it and use the fingers and wrist to manipulate the relatively large ball in the different orthogonal directions. This type of device is subject to airborne contamination.
Another device described as a finger actuated electronic control apparatus by Wedam, U.S. Pat. No. 4,654,647 also requires full attention of the hand in a location apart from the main keyboard while the device is manipulated by a finger. This device could almost be described as a track ball which has a limited range of movement. Mechanically complex, this device would be subject to wear, contamination and by nature be relatively expensive to manufacture.
Light pens are another class of graphic interface devices which are usually picked up and manipulated by the hand to point to a location directly on the computer CRT screen. Since these usually require whole arm movement, they can be very tiring to use for extended time periods. U.S. Pat. No. 4,565,999 by King, et al describes a wireless light pen which is aimed at a special purpose receiving unit while being manipulated by the head. The constant use of the neck muscles for very small precise movements of the head required to aim this light pen would fatigue the user if done for long periods of time. Power consumption and weight would be an issue since the light pen itself must be an active source of light and is wireless. This device would seemingly be expensive to manufacture due to its complex nature.
The next large and important class of graphic input devices are the X-Y digitizers or graphic tablets. In general, these devices use some electronic means of determining the location via X-Y coordinates of a stylus manipulated within the boundaries of some sort of tablet or surface. They are usually large devices (0.5-3 square feet and more), take up quite a bit of space and tend to be expensive. The high price of these devices prevents the great majority of computer users from purchasing them for general use. U.S. Pat. No. 3,904,822 by Kamm, et al teaches an absolute position determining system using a stylus which picks up signals from a conductive grid. In this case, the stylus requires electrical connection to the tablet and is therefore tethered to the tablet. If one were typing on a keyboard and desired to use this device, one would have to remove one's hand from the keyboard and grasp the stylus before data could be entered. Whetstone, et al were awarded U.S. Pat. No. 3,904,821 and teach a similar device based on a somewhat different magnetorestrictive electronic principle. This patent was for an improvement to the Brenner et al device U.S. Pat. No. 3,846,580 because of "certain manufacturing difficulties in providing an accurate positioned array of wires arranged in an x and y coordinate". These digitizers tend to be expensive because of possible manufacturing difficulties. This type of technology would also be difficult to implement in small enough size and weight to be effective for a finger worn device and would still require a tethered stylus. U.S. Pat. No. 4,654,648 to Herrington, et al describes a wireless cursor control system. This system requires a handheld stylus which emits acoustic signals and a sensitive receiver which listens to the stylus and determines its position. Since the stylus is not connected to the system by a wire and emits acoustic energy, it needs an internal power source to operate and this power source will require occasional renewal. The need for a receiver with several sensitive microphones along with proper system calibrations in order to insure and maintain device accuracy will inevitably make this device expensive to manufacture.
Recently, commercially available computer programs have been enhanced to allow the use of graphic interface devices which make certain interactions with the program easier to learn and more efficient to do. However, these "graphic" enhancements have not eliminated the requirement that the computer operator must still use the standard keyboard to enter textual information since it is the most common way to do so. What occurs is an inefficient and tiring constant moving of the hand between keyboard and graphic input device. These devices can also tire the hand and wrist while they are being used. In addition to these operational disadvantages, these devices consume extra space on a desk which may be already crowded. The most popular of these devices are the X-Y digitizing tablet and the mouse. The instant invention is a cross between these two types of devices with a unique location and method of use.
It is very desirable to have an inexpensive device which eliminates the aforementioned disadvantages while enhancing the human-computer interface.